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-rw-r--r--README.md12
-rw-r--r--aes.c18
-rw-r--r--aes.h4
3 files changed, 17 insertions, 17 deletions
diff --git a/README.md b/README.md
index e06cfdf..e32e25e 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,8 @@ void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv)
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
/* Then start encrypting and decrypting with the functions below: */
-void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf);
-void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
@@ -47,21 +47,21 @@ GCC size output when only CTR mode is compiled for ARM:
$ arm-none-eabi-gcc -Os -DCBC=0 -DECB=0 -DCTR=1 -c aes.c
$ size aes.o
text data bss dec hex filename
- 1203 0 0 1203 4b3 aes.o
+ 1343 0 0 1343 53f aes.o
.. and when compiling for the THUMB instruction set, we end up just below 1K in code size.
$ arm-none-eabi-gcc -Os -mthumb -DCBC=0 -DECB=0 -DCTR=1 -c aes.c
$ size aes.o
text data bss dec hex filename
- 955 0 0 955 3bb aes.o
+ 979 0 0 979 3d3 aes.o
I am using the Free Software Foundation, ARM GCC compiler:
$ arm-none-eabi-gcc --version
- arm-none-eabi-gcc (4.8.4-1+11-1) 4.8.4 20141219 (release)
- Copyright (C) 2013 Free Software Foundation, Inc.
+ arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 8-2018-q4-major) 8.2.1 20181213 (release)
+ Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
diff --git a/aes.c b/aes.c
index 18e3f38..776259c 100644
--- a/aes.c
+++ b/aes.c
@@ -240,7 +240,7 @@ void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv)
// This function adds the round key to state.
// The round key is added to the state by an XOR function.
-static void AddRoundKey(uint8_t round,state_t* state,uint8_t* RoundKey)
+static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey)
{
uint8_t i,j;
for (i = 0; i < 4; ++i)
@@ -408,7 +408,7 @@ static void InvShiftRows(state_t* state)
#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
// Cipher is the main function that encrypts the PlainText.
-static void Cipher(state_t* state, uint8_t* RoundKey)
+static void Cipher(state_t* state, const uint8_t* RoundKey)
{
uint8_t round = 0;
@@ -434,7 +434,7 @@ static void Cipher(state_t* state, uint8_t* RoundKey)
}
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
-static void InvCipher(state_t* state,uint8_t* RoundKey)
+static void InvCipher(state_t* state, const uint8_t* RoundKey)
{
uint8_t round = 0;
@@ -466,13 +466,13 @@ static void InvCipher(state_t* state,uint8_t* RoundKey)
#if defined(ECB) && (ECB == 1)
-void AES_ECB_encrypt(struct AES_ctx *ctx, uint8_t* buf)
+void AES_ECB_encrypt(const struct AES_ctx *ctx, uint8_t* buf)
{
// The next function call encrypts the PlainText with the Key using AES algorithm.
Cipher((state_t*)buf, ctx->RoundKey);
}
-void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf)
+void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf)
{
// The next function call decrypts the PlainText with the Key using AES algorithm.
InvCipher((state_t*)buf, ctx->RoundKey);
@@ -488,7 +488,7 @@ void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf)
#if defined(CBC) && (CBC == 1)
-static void XorWithIv(uint8_t* buf, uint8_t* Iv)
+static void XorWithIv(uint8_t* buf, const uint8_t* Iv)
{
uint8_t i;
for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size
@@ -497,7 +497,7 @@ static void XorWithIv(uint8_t* buf, uint8_t* Iv)
}
}
-void AES_CBC_encrypt_buffer(struct AES_ctx *ctx,uint8_t* buf, uint32_t length)
+void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length)
{
uintptr_t i;
uint8_t *Iv = ctx->Iv;
@@ -552,9 +552,9 @@ void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length)
/* Increment Iv and handle overflow */
for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
{
- /* inc will owerflow */
+ /* inc will overflow */
if (ctx->Iv[bi] == 255)
- {
+ {
ctx->Iv[bi] = 0;
continue;
}
diff --git a/aes.h b/aes.h
index 1daab47..87f1471 100644
--- a/aes.h
+++ b/aes.h
@@ -58,8 +58,8 @@ void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
// buffer size is exactly AES_BLOCKLEN bytes;
// you need only AES_init_ctx as IV is not used in ECB
// NB: ECB is considered insecure for most uses
-void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf);
-void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);
#endif // #if defined(ECB) && (ECB == !)